1. When someone dons a fake persona in order to make themselves more attractive to a guy or girl
2. Any time someone is acting out of character
Note: When someone is in sweet mode, call them "sweets" until they snap out of it.
1. Hey guys, I was listening to Nick talk to his girlfriend last night, and he was in sweet mode the whole time. What a fag!
2. Why are you in sweet mode tonight? Snap out of it!
What was that sweets? You sound like a little bitch? Oh ok.