It's definitely the showing of affection for me, for a girl to swallow me. It's like saying "I think the most intimate part of you is 'yummy'." Sounds weird, but after reading some responses-maybe not! So, with me-I like the thought sometimes more than the act itself. If she really likes the taste (the last girl compared it to a Yogurt smoothie lol-don't know if that was meant to make me feel good or the truth...). I have always been told I taste decent-to-good, maybe cuz of what I eat and whatnot.
But the most important thing I've found is to keep in mind who your girl has been with. I'm a super-hygienic guy, clean-shaved, decent-looking-and eat lots of fruit, cereal-that kind of thing that apparently affects your taste. So, if your girl has had scruffy, dirty, guys that openly do gross things-he's not going to have turned her on much. So when I come along, and I won't even let a girl catch me "pooping" lol (let alone farting), she only sees the "yummier" side of me-my face, stomach, and penis usually. So yes, I've been able to change a girl's mind a few times because of how gross other guys were! Plus I don't force anything, and make it as comfortable for the girl as possible, and even teach her how to hold her mouth back as I'm cumming so the gag-reflex doesn't happen, instead of letting it slide down her throat the first time. Then it only gets better, as she squeezes every drop out of it and won't let it go from her mouth when you're sensitive as hell!
So, that gal who said it creates a bond for her is spot on for me actually. It's more intimate for me than regular sex by far, and I feel a total emotional connection that makes me want to just cuddle up like a baby in her arms after she's "taken me all in." And I do literally just snuggle for hours after that. It's apparently "cute!" lol