10-03-2009, 09:28 PM
Regardless of the sex of the third party, the marriage vow has been broken-namely to 'forsaking all others, keep yourself only unto him/her'. So, if the parties are married it definately is. If I was dating someone and they had sexual relations with another person of either gender I would consider it cheating-although obviously there hadn't been a formal declaration of fidelity in the form of a marriage vow.
Have you considered taking longer?