There's a white bump, resembling a pimple under my boyfriend's tongue. it always hurts and when he raises his tongue, it hurts him. what is this?

See a dentist ASAP: You need to see a dentist/ md immediately for proper diagnosis and treatment. Fortunately, the majority of tongue problems are not serious and most can be resolved quickly in some instances, though, a discolored or painful tongue can indicate more serious conditions, including vitamin deficiencies, aids, or oral cancer. For this reason, it is important to seek medical advice.

Sounds like: An aphthous ulcer (canker sore). Typically self limiting - life cycle about 10 days. No treatment necessary will go away in a few days. For discomfort can try using some Benzocaine in orabase on affected area for temporary relief or similar. Ask pharmacist or look in the dental products isle at the drug store. Hope this helps.