I tried everything I could not to tear and also tore badly in my first birth, with my 8' 10' baby. It was a homebirth, with no episiotomy, and in a "Good" pushing position, with perimeal support, and i had labored in water and used oils vaginally for weeks, etc....But i tore badly anyway. It took about 10 months to really be healed, and 18 for full function without pain to be restored.
I'm sorry to tell you, that despite trying very hard again, i also tore badly this time around...I doi really beolieve that some skin is just prone to tearing. This time, my baby was a measly little 5 pounds 10 ounces...and i tore WORSE this time. another homebirth, completely involuntary pushing, hands and knees pisition, labored in water up until pushing, etc....
I just tear, apparently.
I agree that an episiotomy makes things worse, and this time around, you have a decent chance of not tearing, but you also might tear. I knwo of no way to know for sure. I have read many, many stories on here of women who tear with one baby, and then don't tear with an even bigger baby next time....you might very well be one of them!!