I must say I would worry about your credentials as a Deacon if you can’t recognise that going to a strip club is a form of infedelity
Adam, going to a strip club is poor judgment. It is a sin against the sixth commandment, a sin against
chastity. The sin of lust.
It is not a sin against marriage, because the two individuals were NOT married. If they were married, it would still be a sin against chastity, not against marriage.
Going to a strip club is not the sin of
infidelity. From the CCC:
2380
Adultery refers to marital infidelity. When two partners, of whom at least one is married to another party,
have sexual relations - even transient ones - they commit adultery.
If, at the strip club he has contact with a woman such as touching her or she touching him, it is still not the sin of infidelity. It would be the sin of lust.
In all cases, it is a serious breach of trust.
Within the context of what the Church is talking about in the sixth commandment, adultery/infidelity is a very specific sin.
People will say flirting on the internet is “cheating” or “being unfaithful”. People will define “infidelity” broadly in the general context. What I believe the Deacon was driving at is that it is not infidelity
in the context of Church teaching on the essential properties of marriage, and people saying the woman has grounds for nullity based on this “infidelity” are off base. First, there was no infidelity. Secondly, going to a strip club for a bachelor party before you are married does
NOT mean you have no intention of being faithful to your marriage vows when you take them.