What would you do if you keep on running into the same guy everywhere you go?

.A lot of coincidence yeah...I'm typically not paranoid enough to ume that would be a stalking issue (unless I had good reason to think so). If you are interested in him, then definitely speak to him...make a joke about seeing him all the time. If not, then just let it go. It may be that you're noticing him more simply because the situation caught your attention. There may well be others that cross your path as frequently, but you don't notice them.