This is a decent point bring brought up. Kindly allow some flow of thoughts to build a holistic picture. After reading the entire thread I found that no one has brought this up: The language of love. What is it?
Here is the link for those who wish to read more,
http://www.5lovelanguages.com/learn-the-la...love-languages/but also here is the TLDR version:
Time is a language of love. Don't believe me? Read this quote:
"Where a person spends his/her time and money, is where his/her heart is"
Read it again.
Like it or not, things change when your friend couples up or gets married. No longer can you spend ludicrous amounts of time together. Why? Because now they are partly responsible to another person too!
Example: The way Jack behaves should reflect his responsibility toward Jill.
Should Jack still fool around with other girls?
Should Jack make decisions without considering Jill?
(Now here is the major kicker)
Should Jack often find himself alone with another girl, even if it is just talking for long hours. c.f. refer to Language of Love in paragraph 2 and 3.
Most of you say
trust and will most likely dismiss the fact that being together with your best buddy - nothing will happen one. Yeah for you perhaps, but is it so alien to hear this phrase " ... feelings started to develop for so and so.." (or am I now talking out of my ass? You've heard it, you've seen it, maybe even experienced it and it ties back to what I've said earlier.
Therefore in essence, each person should know his or her own limits. Some couples trust is higher and therefore mucking around with good friends of the opposite gender is fine. Maybe they are crystal clear with their boundaries.
Others may prefer to err on the side of caution rather than perhaps? blunder and say that infamous line "... feelings developed"