We’ve all had that awkward moment at the end of an otherwise great networking lunch when the check arrives. Who pays? You might be the person who always asks that the check be split. Or maybe you’re the person who assumes the other person is paying so, when the check arrives you sit there while the other person reaches for her wallet. But in certain scenarios, you should pay.

If you invited her to lunch, you should pay. Especially if you invited her to lunch asking for her assistance or advice. Whether it be career advice or otherwise, if you gained something valuable from the lunch conversation, you should pay. I don’t care if you just had water and she had a margarita, you should pay. If you can’t afford to pay for lunch then don’t ask her to go: suggest meeting for coffee instead.

Now, there are some instances when your mentor or the person you invited insists on paying. In that case, politely offer to pay again and if she still insists then thank her for lunch and tell her the next lunch is on you. Be sure to follow up with an email or text thanking her for lunch and make a mental note to schedule lunch in the future.

Knowing when you should pay for lunch will ensure that you aren’t straining relationships with friends and mentors because you didn’t know that you should have paid.