Is it normal to kiss for three hours?
Unusual.Less common, but harmless
Three hours of kissing is a long time, but it can happen when you’re really into each other and lose track of time. It’s fine as long as you both want to keep going and feel comfortable.
Three hours is definitely an enthusiastic make-out session, but it’s not alarming or unheard of—especially with a new partner or when the chemistry is strong. Some people are happy to kiss for ages; others would be ready for a snack and a change of activity much sooner.
The only real measure is whether you’re both enjoying it. Take a break if your lips or jaw get sore, and check in if either of you seems uncomfortable. There’s no required stopping time.