Not exactly, no. "Olla naimisissa" comes from the noun "naiminen" (getting married). "Naiminen" also has a colloquial meaning of having sex. The noun derives from the verb "naida", which means "to marry someone" or colloquially to have sex. So they're two different meanings.
Due to this, one should be careful when using the word "naida". Using it with a wrong form of an object (or without one) can be misunderstood as something quite different.
Ovat = (they) are. Olette = (plural you) are. Olemme = (we) are. So somewhat like you can't say "We you're married", you can't say "Me olette naimisissa".
English can get confusing with its singular and plural you, singular they, "are" being used for both you's as well as the rest of the plural forms... So I guess it's harder for native English speakers to learn Finnish because to them these things are natural.