Hahaha. As everyone else has said, this is a classic. My abusive ex did the square root of fuck all for DC, when we split he wanted full custody, then he wanted them alternate weeks, then it was all the school holidays. At first I was so scared I was physically sick - I'm not a particularly fussy or overprotective parent but a week in the sole company of my ex would have been awful for the DC. Then I realised what he was trying to do and called his bluff. Agreed on the extra days, with a view to building up more. Well, he never showed up. He came and picked them up for his four hours on a Sunday, but never once followed through on the extra days HE demanded.
Eventually even the Sundays petered out, he would go months without turning up or answering his phone. Very distressing for DC. The last time he phoned (after a 3 month absence) he demanded to take them out the following day, but we were booked to go and see a big event and I told him no, and not to bother contacting me again unless he was willing to stick to regular contact.
Of course this gave him ample fuel to accuse me of "stopping him seeing DC" but he had plenty of money and he was welcome to take me to court. Which he never did.
He has not seen the DC or made contact in any way in almost a decade. During that time I've known friends and relatives go through similar, as well as reading posts on Mumsnet where the man has said the same thing..it's almost word for word the same nonsense as my ex came out with, and in nearly ten years NOT ONE has pursued full custody, or even 50/50. At the most it's EOW. If the DC are lucky.
Custody cases take effort, and they simply don't care enough