How to Determine if Someone is GF Material

Hey all - Been seeing someone for about 2 months now, and a bit torn which direction to take this. I really vibe with this person outside the bedroom, and I'm not embarrassed to be around them in public. No red flags yet and she's my type on paper (Tall, blonde, career focused, has her own hobbies). Iv'e met some of her friends and she's met one of mine. However, the sex is good, but not great as opposed to other people I've seen in the past. My question is A) When should I bring up where do we see this going and B) Is it normal to be in a monogamous relationship, but still think "what if" in terms of seeing other partners? I've never been in a serious relationship, so that would be a brave new world for me. avilench .