First of all, this is just some funny thoughs madeup by André. We must remember that Hamtaro is a show for kids, so obviously they wont talk about things like homosexuality. However, fandom and Hamtaro reactions in the OVAs made us think that there's "something more" between this two hamsters that it's expected. Specially from Hamtaro's side.

OVA 3 - Ham-hams and the Prince of Rainbow Land
When Hamtaro first met Bo, he keep chasing him, not even letting him fly and leave to his hometown. Along all this time, both are unnecesary blushed, Hamtaro being the most blushed one. We can suppose this is because Hamtaro is excited to go to Rainbow Land, specially because when he and Bo stick their faces, he says "Waku waku", translated as "I'm excited", but... think twice, could be that he's excited about going with Bo to Rainbow Land?

When they reach Rainbow Land, Hamtaro is quite excited, and then Bo decide that Hamtaro would be his butler. Hamtaro is quite excited with the idea, and during all the OVA he keep playing that role. He refers to Bo as his "Master" and ask him to carry his umbrella, give him a massage or even carry him when he's tired. Also, as his "butler", Hamtaro decide to grab him when he's taking some tea with the girls. Hamtaro don't care about the girls, and he look jealous about Bo being with the girls, don't he?

And, of course, the end. Bo's most precious treasure is Hamtaro's "friendship". Pretty obvious stuff~ I think his "friendship" is gonna be farther than we expect~