Boy or Girl?

Question
I recently bought two guinea pigs, and I have no experience with them at all, so I can't tell. I'm a first-time owner. Anyway, I bought them from a place that was absolutely TERRIBLE. The guy practically man-handled them, and I have a feeling that, if I hadn't bought them when I did, they would've wound up as boa constrictor food. The guy told me they were both males, but I seriously doubt that based on the way they're acting. They're always together, cuddling and stuff. The bigger one I think is the female. I notice that the bigger one will be, like, eating or something, and then the smaller one will come up and start doing this weird little walk around the bigger one and making a weird noise like a motorboat or something. The bigger one will then start making a high-pitched squeak, like it's begging for food. What? What does that mean? Can you help, please?

If it helps, the bigger one has, like, a calico cat pattern, and the smaller one is black-and-white.

Answer

Baby boar  

baby sow   Well I can tell you that the little guy doing the wiggle dance is most definitely a boar. That swaying and purring that they do is called "rumblestrutting."  You will also notice that he presses his rear down closer to the ground as he sways.

All male animals have some kind of flirtatious dance they do when trying to get the attention of the girls. I posted a couple of pictures last night for a young lady who wasn't sure of the sex of her new babies. I've posted them again for you.  

If they are young pigs the boys will behave that way toward one another because they haven't yet figured out that the "other guy" is not a girl. They're like teenage boys who are hot for anything that moves.

If the bigger pig is indeed a sow, the sound she is making is a high pitched "leave me alone, I'm not interested" squeal. So it does sound like you may have one of each sex.

A sow will often do something that is unique to guinea pigs, especially if she's not ready for breeding.  She will arch her back and shoot a stream of urine right in the face of her suitor. They never miss, and it cools the jets on the boar immediately!  Just as in humans the sex is always at the pleasure of the female.

An older boar is most obvious to tell as the testicles are much larger than in these pictures. In a sow you can spread the genitals and see the shiny membranes inside.

I hope these pictures give you some help. If your pigs are still small I would separate them unless you are ready for babies. A sow can become pregnant very very young and although it will not hurt her, it's best to let her grow up a little before becoming a mom.