What does She always drank it out of the can mean?

Dig a grave, and by the way, let’s talk about the funny point of this line. At that time, I understood instantly after watching Six People's Row several times that purity was far away from me~~~

Ross's wife is a lesbian, and it was difficult to let go after the divorce. When Chandler and Joey were assembling furniture at Ross' house, Ross took out a can of his wife's favorite beer and said thoughtfully: She always drank it out of the can. I should have known. It means, "She always drinks from the can. I should have discovered it a long time ago..."

What should I have discovered a long time ago... Of course, it means that I should have discovered that she is a lesbian because she I always like to lick the can. What does the mouth of a beer can look like? You can decide for yourself. I don’t need to explain clearly how lesbians can be intimate. So, the punchline of this sentence was very, very obscure at the time. An adult joke.

There is also a joke about CUP. When Ross's wife gave birth in the hospital, Rachel fell in love with a doctor who was flattering in every way. As a result, the doctor rejected her with a subtle cup joke, which almost compared the cup to a certain part of a woman. Rachel almost vomited at that time...