@Summerfun54321
Fine for him to appreciate his ex, but to give gifts to his wife and ex wife for the same occasion at the same time is asking for a comparison and asking for trouble. Either he keeps doing it and doesn’t tell you what the gift is, or he stops doing it. I think it’s fine to tell him you don’t want to know as you’ll naturally be comparing.
I agree with this but disagree with the idea that he should keep buying the ex wife gifts and not tell his actual^ wife what he is buying. That is literally 'doing things behind her back' territory.
IMO, no married man should be buying gifts for other women that he is not related to. It's weird and inappropriate. There is the occasional situation in which it's OK, like if it's Christmas, and the man is buying gifts for all the women in the office. But to just buy for one, and keep buying for that same one, (when he is married,) is wrong.
Some people say that if a man has been friends with a woman for a few years before he met his wife, (and they used to exchange gifts) it's OK to stay close with that woman, and still exchange gifts and stay close friends etc. But IMO it's not. The dynamic of the friendship HAS to change when you get married. Your spouse is No 1 priority now. If you don't want to adhere to that, then don't get married.
As I said earlier, when you get married, your devotion and loyalty is (or SHOULD be) to your spouse. Making a fuss of a person of the opposite sex and buying them stuff (especially an EX,) is just weird and inappropriate.
I have a friend who is 45 now, and got married at 30. For the first ten years of their marriage, her DH always had a female friend at work. If any new woman joined the company, he would try to make her his 'friend.' Only the single ones of course - never the married ones. He had 4 or 5 close female 'friends' in the workplace over ten years!
Whenever my friend and he went anywhere for a daytrip or a holiday, he would scoot around looking for a gift for his current (female) close friend. Poring over things and taking time to get the right 'gift.' She told him quite a few times that it upset her, and was inconsiderate of her and her feelings.
He even did it on a trip they went on (to Paris) for their 5th wedding anniversary. Spent hours looking for a gift for 'Sue' at work. In addition, these women used to buy him gifts too! Never her, (and never joint gifts,) just him. In fact, they didn't want to know her.
He told her she was silly to make a fuss, and she has no need to be jealous, coz she 'is just a friend.' My friend said she thinks he likes it that she is upset. She said it's not even jealousy at all, it's the fact that he is being horribly disrespectful, and not considering her feelings, and that it's a nasty way to treat your wife.
So fast forward a few years to her 40th birthday (10 years after they got married.) A man at work (who started just a few months earlier,) bought her a big bunch of roses and a box of chocolates, and a nice card. You guessed it, her husband went ballistic. Red with rage. Like who the fuck does he think he is, buying MY WIFE fucking flowers and chocolates?' 
She said she was gobsmacked.
'Well you have spent the last ten years buying gifts for your female 'friends' but no man is allowed to buy anything for me?' she said. He said 'well THEY were all single, I would never buy a fucking married woman anything. I wouldn't stoop so low as to disrespect her husband like that.'
My friend said 'no, but you are happy to stoop so low as to disrespect ME, your wife, by constantly buying gifts for other women. Even on our wedding anniversary trips! And they constantly bought you gifts back. For your birthday, for Christmas, from their holidays. Nothing for me, just you!'
He still didn't 'get' it, and thought it was fine, because these women were single, and were just his friends. My friend said well it's NOT OK, and I am glad you're fucked off and upset that this man has bought me flowers and chocolates. Now you know how you have made ME feel for the past 10 or 11 years.
3 years later, they broke up. Apparently her husband didn't like it when she became good friends with this man, and they bought each other gifts, and became close friends. It's OK when HE does it, but not OK when SHE does.
Sorry for the ramble there Just wanted to illustrate an example of how (IMO) it's not cool to keep buying gifts for a member of the opposite sex, when you're married. It gives the wrong signals out, and blurs the lines between friendship and something more^ than friendship.