Tom Cruise and Katie Holmes are presently arguing over having another baby,as the Top Gun actor wants his daughter Suri to have a sibling,sources say. An English friend of the celebrity couple who visited them in Boston where they recently moved in,revealed that they have differences on the issue. They are arguing a lot because Tom feels he is getting on in age [hes 47 and he thinks Katie owes it to him and Suri to get pregnant. He says he would be in his 60s while the child was young and thats still just about OK to share in the childs life, the Daily Express quoted a source as saying. The insider added: Katie feels Tom is more wound up about this than hes ever been and relations between them are at a really tricky stage. Shes only 30 and shes not sure about having another baby right now but then she feels guilty about Suri being an only child,especially as she grew up in a big family herself. According to sources,Cruises Wichita co-star and beauty Cameron Diaz has increased the tension between the two after exclaiming that it would be nice for Suri to have a brother or a sister. The insider said: Cameron is besotted with Suri and innocently said to Tom in front of Katie how nice it would be for her to have a sibling to play with. She didnt know what a hot potato the subject is between the two and after Cameron left their house they had another argument. Cruises insistence on having another baby may be because he envies David and Victoria Beckhams large family,believes the source. The snitch further added: Tom gets on really well with David and once they had a night in together watching a couple of films while the Beckham boys wandered in and out giving their dad a kiss and a hug. It made Tom quite envious. He said he would really love to have a little brother for Suri.