Technically there's no problem. it's up to your hosting company. My hobby is/was collecting niche domains, and I've got more than one hosting account with 80 or so domains on the same IP. Google doesn't seem to like me though, and I've never really understood this. If I register a domain for gay gloryholes, and one for gay dogging, and I link to them both from a general gay site, I don't see what the problem is. I also like to collect sub-niche and cross-over niche domains, and I would have thought that that would have been great for google. One example is a recent site for galleries of girls peeing while they are tied up.
