Tang Sanzang, realizing he had been a bit hasty, knew it was somewhat suspicious to suggest drinking strong liquor on a first date with a woman—it indeed resembled trying to get her drunk for his own purposes. So he offered a remedy, "No more liquor, let's drink tea instead!"
Bai Huaxiu, of course, had no idea she was merely looking for a chat with a bald man—this guy had already escalated to dating and having children.
She was merely surprised that Tang Sanzang, a monk, would actually suggest drinking alcohol...
Although monks are allowed to drink mild, vegetarian alcohol, a true master doesn't even drink that.
But upon further reflection, apart from his strength and attire, there seemed to be little else about this fellow that related to a monk, so she let it go.