The friar doesn't ask him if he has spent the night with Juliet. With Rosaline, not with Juliet.
Romeo denies spending the night with Juliet and tells Friar Laurence that he only spent time talking and exchanging vows with her. He explains that they were married that day.
Friar Laurence married off Romeo and Juliet.
Friar Laurence is the friar who marries Romeo and Juliet.
Friar Lawrence married Romeo and Juliet in his cell.
Juliet, Romeo, Tybalt, Nurse, Benvolio Or . . . Juliet, Romeo, Friar Lawrence, Nurse, Capulet Or . . . Juliet, Romeo, Friar Lawrence, Capulet, Tybalt Or . . . Juliet, Romeo, Capulet, Mercutio, Tybalt Or basically Romeo and Juliet and any three of Nurse, Friar, Capulet, Mercutio, or Tybalt.
Romeo, Juliet, and Friar Lawrence are in Friar Lawrence's cell.
If Friar John has not yet been to Mantua, Romeo does not know that he is supposed to come back to Verona and get Juliet out of the tomb. Of course, he would not know that anyway because Friar Laurence sent his message to Friar John at a time when he thought Juliet would take the potion on Wednesday night, when in fact she took it Tuesday night. So, even if Romeo had got Friar John's message, he still would have been a day too late, by which time Juliet would have suffocated. Why the Friar did not spend the entire night of Wednesday/Thursday at the tomb with an iron crow is impossible to understand.
Friar Lawrence wants Romeo to do different things depending on what part of the play you are talking about. When they first meet, the friar tells Romeo to go slowly in his relationship with Juliet (as if!).
Friar Lawrence was the priest in Romeo and Juliet
The friar.
Friar Lawence
It was both Romeo's and Juliet's idea to marry eachother.
Romeo shows up at the friar's doorstep in the early morning. He has not slept all night. He's been with a girl. The last girl the friar heard about Romeo liking was Rosaline, only the day before. All of a sudden, Romeo's talking about this Juliet--and he wants to marry her? I guess the friar's surprised.