I guess my situation was/is a bit easier because the kids were a little older and already had some good values in place. As far as stepping into the father/male role model position, that was a bit unusual in my case as although their father was physically present in their lives, he really wasn't actively involved. He is somewhat self-absorbed and really didn't do things just for the kids. E.g., while he would ask them to do things with him, it was more of an afterthought and a last minute type of thing such as "'I'm going to to X, you wanna come? We're leaving in 10 minutes.." Sorta like they were an afterthought.
For what its worth he lived with his mother off and on for most of his adult liife, constantly in and out of rehab. It was on one of these "vacations" that he met his current wife of two years...a bona fide recent heiress also in rehab. He steps and fetches for her to keep the golden goose happy. The kids have seen him go from being broke to a move to Santa Barbara with a big house, boats, cars (a limited edition truck to a Boxter S to a 996 TT in just 6 months...and yup its a tip
), hair transplants, gaudy jewelry, etc etc.
I was concerned on how the kids would react to this, but my worries were for naught. When he announced his early retirement at 45 stating that he and his new wife just had too much money for him to have to work, it was very clear they had lost whatever respect they had for him.
Because of my step kids, I found the joy of doing things or teaching them things I knew as a child/young adult. Because it was siomething that interested my step son, I've gotten back into hunting, fishing, dirt bikes, tennis, etc...stuff his dad never did with him. And suprisingly, he has made an effort to take interest in things that I'm interested in such as racing, working on cars/bikes. I enjoy supporting them in their athletics and activities.
And its pretty cool and something of an ego boost when they come to you with their problems and ask for help wth life decisions and truly take your input into consideration. Like I said earlier, I've been blessed. But my experience has been totally positive. In fact I'd go so far as to say I'm getting more out of the deal than they are.