I'm an opportunist...?
If I'm single and there's sex on the table, I'll take it. :P
If there's a chance for romance with an awesome girl on the table though, I'll take it, and dedicate myself to it. I'm still an unmarried 25 year old not settled enough career wise to "settle" but I definitely see marriage and family rearing as very important in my future.
I've been through my fair share-- tons and tons (and tons) of rejection, a number of one night stands, a number of sex friends, drunken hook-ups, a single orgy, puppy dog love, puppy dog heart break, sexy/romantic affairs with older women, and a crushing break up with a friend of 9 years who I thought would be the love of my life. Right now I'm in a serious relationship with a terrific girl, who has shown me for the first time what it's like to be equally dedicated and fully dedicated to making it work. Hey, it just might.
At the very least, I'm older than you, so I'd hope I have some useful insight. :P