So, I've been with my GF for about 7 months now. She's 5 years older than me (I'm 25, she's 30).

Why am I so bothered when she talks about her sexual past? One night stands, guys she was seeing, everything bothers me, even when she says that she kissed a random guy on a night out. Why is this?

The thing that bothers me most is that she slept with a colleague that we both work with before we met last year and it makes me feel shit every time I see him (she didn't tell me about this, I found out through a friend).

Should I just next her?