I think my dad is having a mid-life crisis?

So, my dad is still married to my step-monster. They've talked about getting a divorce, but neither of them have actually taken any steps in progressing towards a divorce.
My dad was seeing this lady who is 43 (He's 43 also). They were together for about a year and a couple months, they finally got engaged. Then, three weeks ago (A month after they got engaged) he got drunk on some Jag and told her to get out. The day after, he started dating this 26 year old lady he works with. (Well, he did work with her....he quit that job and started a new job so their relationship wouldn't become a problem). Now, she and he are engaged.
I don't have a problem with his new lady. She's a great person....and fun to be around. Yes, I believe age is just a number. She's actually bringing out the person in him I knew before he married my current step monster.
But, he's been acting like he's trying to regain his youth. Started using a hair dye....got his ear pierced, and is talking about buying a Harley (The Harley thing he's always been into....so that's not really a big issue.)
Is this a mid-life crisis....or what?

 

I've always thought the term "mid-life crisis" was rather negative.

How about "intentional life transition?"

He is an adult who has decided to hang-on to (or to recapture) his youth.

I've seen people in their 60's do it as well as people in their 20's.

It seems often to be accompanied by the end of a relationship and/or the beginning of a relationship.

He probably feels that the way things were before weren't working all that well for him so some changes need to be made.