What are the bases. PLEASE HELP

[OrigamiKing]

My friends are always talking about the bases(not baseball) and stuff but I can never understand what they mean... any help? I'm guessing 4th base is sex but what about the others

[sieg]

i believes 1st base is kissing
2nd base is going for breasts
3rd is intercourse.

[CharlieHorse]

according to Alaska:
-French
-Finger
-Fuck

XD

[Emerald Dream]

Actually, the "bases" are as follows:

1st - kissing
2nd - feeling up, groping, often associated with breasts
3rd - oral sex
4th/home - intercourse