Either a form of humiliating sex or sex with a lack of respect for the one being sexed on.

A Bloomer is someone with a bright outlook on life who is optimistic in nature. Bloomer's frolic in every opportunity to be happy and try to make the most out of life. The opposite of a Bloomer is a Doomer. The term Bloomer originated specifically as a counter to the Doomer on sites especially like 4Chan.

Whatever you think it means is exactly what it is