I've been in a lab group which meets 3 hours a week with this lady for half a semester, and she's really fun to be around. That's enough time knowing her, right? I just texted her asking if she wanted to get tea with me next week. Why do I feel so horribly ashamed like I'm overstepping her boundaries completely? Should I? If no, how can I stop feeling this way every time I express interest in someone? If yes, how should expression I interest without being out of line?

Update: she agrees fairly enthusiastically. Now I think I'll just go with the flow