I have this big red spot on my penis head, you can tell the texture is different on it, its normal temp with lines in it? Saturday night I had oral sex with my girl for the first time ever, we have never had sexual contact with anyone in our lives until e

Very . Very difficult to answer without a clinical examination. It could be psoriasis (common to occur a few days after sex due to the friction/irritation), eczema, or dermatitis, or other possibilities. I would recommend you see a dermatologist for proper diagnosis and treatment options. Read more about psoriasis below. I hope that helps.