Taking the comic "seriously" as I like to do, I have thought about Swampy and Sandy, and why they're together.
"-He's a nice guy, treats her right, and makes her hit E above high C with just his tongue?"-Doc Nickel.
Well, that would pretty much cover it, but there IS more. There's 2 sides to the "what do they see in each other" equation.
One- what does Swampy see in Sandy, and two- what does Sandy see in Swampy. If there aren't sufficient answers to both in a relationship, it's not going to "go the distance", at least not and be a HEALTHY relationship.
What does Swampy see in Sandy? She's good-looking, she's nice, and she's organized. (He could use some organizing.) That's what we can see- and we're not really privy to all the little details.
What does Sandy see in Swampy? He actually IS a nice guy who treats her right. But let's dig a little deeper. Sandy is really organized and really straight-laced. In their relationship, she seems to realize that she could USE a little chaos and disorganization to keep her life from stagnating. Also, watch out for the quiet ones. You never really know what's going on in their lives. They just don't tell you what's going on. (I'm reminded of my own marriage and what boring people we appear to be to the unobservant.) Sandy really hides a wild side. We know Sandy's got a piercing, and not in a spot you'd probably guess. (Swampy pointed out Pirta had a matching one when she was painting, and got his face painted for looking. ("Totally worth it." Yeah, we would have said the same, Swampy.) We also know that Swampy keeps just grabbing Sandy for TLC- and she's consenting to spontaneous fun each time, whether in the broom closet, or whatever. She was certainly consenting to the unfinished basement room with the electric "candles" Swampy set up.
So, Swampy is comfortable with Sandy's public and private sides- and she's pretty private about that private side! And he adds fun and flavor to her life. And he treats her right. So, she puts up with some of his comments here and there- and he puts up with things from her, also, that cuts both ways.
So, I think I've been slowly surprised to see how well they mesh.