I don't think it is at all. I can literally count on one hand how many times Pakistanis have married other S.Asian cultures (nothing wrong Islamically of course), boy or girl. Even according to stats Pakistanis are the second most inward marrying community among all South Asian groups, I believe it is 9% who marry outside, nearly all men, I'd say even lower.
White British (4%) were least likely to be in inter-ethnic relationships, followed by Bangladeshi (7%), Pakistani (9%) and Indian (12%) ethnic groups
https://www.ons.gov.uk/peoplepopula...ellusaboutinterethnicrelationships/2014-07-03