I went thru the exact same situation. I was there for my friend who actually never shunned me nor his deceased mother, who always thought of me as a son. Absolute silence as I entered the funeral home. Only one brother acknowledged my presence by the slightest of nods.
I stood by my friend who embraced me and we both cried over the death of his mother.
I thought it would be hard; it wasn't. The love I felt for my friend and his mother was bigger and stronger than whatever ill feelings the rest of the people may have had for me...
I stood tall and proud and shameless as my tears flowed... mute testimony of what true love between friends is.
The lesson taught by me being there all circumstances nontwithstanding touched more than one heart that day...
May love be the reason for you to be there...