ON THE HEELS of last week's congressional mugging of the District government's attempt to reform its laws relating to sexual conduct comes congressional tinkering with the city's attempts to begin legal gambling. Like the reform of the sexual assault laws, the status of gambling here has little to do with the federal presence in the city, and there is no valid reason for Congress to deny the will of the city's voters to have a lottery, bingo and raffles. But there is one important difference between what Congress did in cancelling the earlier reform and what it is on the verge of doing to the gambling law. Congress has already approved of legal gambling in the city. It did so when it failed to veto the law last year during the 30-day period Congress has in which to review all new laws signed by the mayor.

Gambling in the city nevertheless remains at risk because the people on the Hill can opt to disapprove of any city budget that includes money for programs they don't like--such as funding the work necessary to get the legal lottery and numbers game started. Last month the House did just that, passing the city's budget for fiscal year 1982 only after $628,000 allocated for starting the lottery had been taken out. The Senate will now have to decide whether to approve the budget. If the Senate lops off the money for gambling, the city will not be able to start the legal lotteries and numbers games that the voters asked for in a referendum a year ago.

While Congress squelches the city's ability to start legal gambling, the D.C. Lottery and Charitable Games Control Board is preparing to accept bids from private companies to set up the computer system that will control the lottery. The board has already written the regulations that will govern gambling. In fact, the board is ready to start the lotteries and numbers game in the city, and could do so without getting any money from Congress, according to its chairman, Brant Coopersmith. Mr. Coopersmith estimates that an instant game could quickly net the city about $5 million, and pay for the cost of getting started. But, as part of the District government, the gambling board cannot legally spend money on any expense not approved by Congress. So, to satisfy the regulations, the board must request money it does not really need and face the possibility that Congress may not approve it.

In the city's fiscal '83 budget, Mayor Barry has included $25 million revenue from the legal lottery. For a city with financial troubles, the loss of that money is no small consideration. Congress might take note of this. But the heart of the matter is really that the voters of this city asked that legal gambling be put on the ballot, and approved it in limited forms after defeating one version that included jai alai and dog racing, and Congress then allowed that law to go into effect by not using its veto power. Legal gambling--in certain limited forms-- has gone through every step of the home rule process in this city to become law.

Congress is running wild over the District at the moment, having no constituents to answer to for revoking the democratic process in this city, while reaping the benefit of applause from whatever group is opposed to whatever the city is trying to do at the moment. Instead of trying for snake eyes, a double on their disgraceful performance in vetoing the reform of the sexual assault law, Congress should butt out of the gambling issue. Congress did not speak up when it had the chance to stop gambling from becoming law, and it should not try to mug it in a back-alley budget maneuver now.