Tough situation. I honestly think it's important to say something. But it should be along the lines of "Hey Babe, I really care about you and love our relationship, but I'm noticing it hurts my feelings when you flirt with so and so". You're not gonna like this advice and of course your relationship has multifactorial pieces, but if your partner starts turning it around on you and saying you're insecure, then you should know there should be a possibility of you exiting the relationship. Research has shown if you're around someone more, you begin to like them and start relationships due to proximity.

but show up at your partner's work place (ideally when s/he is not there -say if s/he goes out for lunch) and time it so that this other person is there when you show up and mention you're "so&so's partner" and just wanted to surprise him/her for lunch.

Where there's smoke there's fire. Trust your instincts. Hopefully you don't live together because it will make it easier to distance yourself. I went theo the same thing.. totally trusted my instincts as much as I wanted to ignore them and I was completely right. I totally stopped communicating with him all together and low and behold he never called me, texted me.. nothing. They ended up together. He never even asked me what happened. He didn't care. I suggest you just move on. If someone is WITH you then they won't be flirting with someone else. That's just blatant disregard for your emotions and your life. Fuck them.

That he won't act on it? Are you the same person who confessed her partner visited his workplace when he wasn't working just to see his beautiful coworker? They're already flirting and spending time together when not (supposed to be) working, I don't see where they'd draw the line. In any case, why do you want to be with someone who doesn't care about your feelings, and is making you insecure about yourself? Someone who'd rather see a coworker than taking care of you when you have a bad day--making you feel lonely and neglected? That are better people out there. And I think it's still better to be alone than with someone who doesn't care.

that's a tough and helpless position to be in, just remember you are the one she chose to be with.

I was in a relationship where my partner was very open about liking other people. I think it hurts no matter if they are open about it or not. I would encourage you to look at your goals and future with this person. You may be able to get some clarity and see if this is a bump in the road you travel together or if this is it. Yes it feels horrible, ugly and insecure to say. But YOU matter in this and your feelings matter because this is your relationship. Please separate financial matters from your feelings, do not stay unhappy, unloved or unsure for rent or food. You will get back on your feet or vice versa they will. Wishing you luck.

Can sometimes just be harmless fun. I do it all the time and it never amounts to much. Maybe your mate is simply enjoying their colleague's company. You on the other hand have the right to be a little jealous. Look for signs of a deepening development though, and if so, maybe then you should have a talk about it. Wishing you all the best

If your partner is flirting with other people, it is hurtful and completely disrespectful towards you and the relationship. Don't put the blame on yourself for feeling insecure! If something is bothering you, a good relationship involves communication. Your partner should be supportive, understanding, and want to you feel good about yourself! If they get frustrated at you for voicing your honest feelings, it sounds like they don't care about your wellbeing. That would probably be a sign that this relationship isn't worth hanging onto.

from my experience, as soon as you stop worrying about your better half and start inviting them to do things you want to do, its kinda like killing two birds.. you find that you aren't afraid to go out on your own and this is liberating and builds confidence and as soon as the other realizes they are not the only thing you live for they cant help themselves but try to get your attention.. good luck on your new freedom .. otherwise your living vicariously.