A long story cut short. Known my friend for a good 10 or so years, known his father for about 5. His father is divorced and has been as long as I've known him. I've always gotten along with him fine but in the last few years it's turned quite flirty. It hasn't been serious flirting, just joke/light flirting and my friend hasn't commented on it. In the last few months it's turned more serious and I've caught him checking me out several times, the flirting's been heavier (especially if we've been alone) and he's been texting me. At first I went along with it but then I started replying as neutrally as I could. In the last couple of weeks he's texted me and put forward the idea of hooking up for sex (I didn't reply) and today he's sending me pictures of himself. I haven't replied yet and I really don't know how to. Not that age matters, but I'm 32 and the father is late 40's. Even though I'm single and he's single there's obviously the issue of his son and my friend. And as far as I knew, his father was straight. I know I should say no but there's something about him that just makes me want to say yes. He's not my type but I can't help but be a little attracted to him. Maybe not quite a long story cut short but it's got me confused basically.