Quick question for TRP,

I'm 20, in college, and have 4 roommates that are integrated fairly deeply into my life. As a result, they've seen a lot of women come and go, from 'plate' to LTR. My question is, how do I react to these friends trying to fuck girls that I've been involved with in the past? Granted that I've moved on to other women.

My gut reaction is to be angry that someone is treading on territory that used to be mine, and I'd really like to feel nothing and just share the wealth with my friends.

What's the proper way an adult male should react to something like this? So far, I haven't reacted because I have a small hamster of emotions about the subject that goes from anger to apathy to pity for my friends for not being able to find their own women.

Thank you TRP.