I'm sorry to hear of your dilemma.
Adultery is generally defined as sexual intercourse between a married person and a third party. Like rape, adultery does not require completion or orgasm....but the slightest of penetration.
A single instance of sexual intercourse will qualify as adultery in the State of Ohio. While it is unlikely than an Ohio court would find that kissing and fondling would be sufficient to prove adultery, in the matter of Jacobellis v. Ohio,
378 U.S. 184, 197,XXXXX 1676 (1964), the court essentially held that many physical acts short of sexual intercourse would be grounds for proving adultery---among them, oral sex and anal sex.
So, today, in Ohio you can expect the court to allow the ground of adultery in a divorce action where one spouse can show that the other engaged in sexual intercourse, oral sex or anal sex with a third party.
I wish you the best in 2010.